1. Field of the Invention
This invention relates to such a lamination apparatus utilized as to form lamination layers of transparent or semitransparent laminate film with adhesive agents on one side of the surfaces pasted on the surfaces of printed posters and advertising fliers, computer output media and so forth (called media hereafter) in order to provide protection to surfaces of printed matters leading to improved water and weather resistance.
2. Prior Art
An original roll of laminate film is composed of a long sheet of lamination layers wound around a core roll (pasteboard roll). Lamination layers are made of transparent or semitransparent film like polyester, vinyl chloride and so forth with adhesive agents applied on one side of the surfaces and detachable paper placed on it.
As shown in the side view of FIG. 5, the conventional lamination apparatus to coat a surface of media with laminate film as above mentioned is furnished with side plates 11 fixed in parallel with each other at the left and right side of the frames as supporting structure for bearings. Those bearings hold a shaft 31 of a carry roller 3, a shaft 41 supporting a core roll of original roll 4 of laminate film A, a shaft 51 supporting a core roll of original roll 5 of carry film C, a shaft 42 for a core roll to rewind sheet of pattern paper B detached from laminate film A, and a shaft of an idler roller 43 respectively.
In addition a table 2 to send media M is accommodated in the space between side plates 11 together with an idler roller 21 the shaft of which is held by bearings.
A carry roller 3 supported by right and left side plates 11 is driven by a motor 30 and a pressure roller 6 is also installed on top of the carry roller 3 to make a pair each other.
The shaft of pressure roller 6 is held by bearings installed in the movable plate 61. One end of the movable plate 61 is supported by the pivot 62 installed in the side plate 11 and the other end is moved up and down by the motion of cam 64 and rod 65 given by the lever 63 in order to keep the pressure roller 6 away from the carry roller 3. The spring 66 gives force to the pressure roller 6 and such force can be adjusted by turn of a screw rod 67 through a handle 68.
The lever 63 be handled by the operator to keep the pressure roller 6 away from the carry roller 3, the original roll 5 of the carry film C is set on the shaft 51 followed by the carry film C passing on the idler roller 21 and the table 2 to be inserted in the space between the carry roller 3 and the pressure roller 6. Then original roll of laminate film A is set on the shaft 41 and a sheet of pattern paper B peeled off laminate film A is rewound around the core roll supported by the shaft 42 through the idler roller 43. On the other hand, laminate film A with adhesive surface exposed is inserted together with a carry film C in the space between the carry roller 3 and the pressure roller 6 followed by the pressure roller 6 being lowered by the operation of lever 63.
With media M placed on the carry film C covering the surface of the table 2 an operator steps on the foot switch to turn a motor 30, the shaft 31 of the carry roller 3 and the shaft 42 of the core roll to rewind the sheet of peeled off pattern paper B. Media M is drawn together with the carry film C in the space between the carry roller 3 and the pressure roller 6 by rotation of the carry roller 3. At that time the laminate film A carried along the surface of the pressure roller 6 and with adhesive surface exposed is pasted on the surface of media M and discharged on a table 8 tilted at the back. On the other hand, the sheet of peeled off pattern paper B is rewound around the core roll supported by the shaft 42.
In operation of the conventional lamination apparatus the brakes are applied to the shaft 41 holding a core roll (pasteboard tube) of an original roll 4 for the laminate film A in order to draw out the laminate film A under tension. In the same way the brakes are applied also to the shaft 51 holding a core roll (pasteboard tube) of original roll 5 for the carry film C. On the other hand, a clutch is fitted to the shaft 42 to drive the core roll (pasteboard tube) for the sheet of pattern paper B that is rewound around it.
If core rolls for respective shafts of 41, 42 and 51 slip on the shafts on the occasion of fitting of those core rolls proper tension specified in advance cannot be achieved by brakes or a clutch. It is feared that the laminate film A and the carry film C may become slack, wrinkled and or specked without proper tension and may lead to bad quality.
Therefore as shown in oblique view of FIG. 6 and cross section of FIG. 7, the shaft 8 is cut at two (2) locations opposite each other on the circumference in order to have flat grooves 81 running the full length of the shaft 8. In each groove 81, a rubber cord 82 slightly thicker than that of groove 81 but slightly shorter than that of groove 81 is fitted with both ends fixed. If the fitted core roll 83 slip, a rubber cord is moved to such narrow corner of the space 84 as made between the inside surface of the core roll 83 and the flat groove 81. Thus slip of the core roll 83 is restrained by torque greater than given by brakes and/or a clutch.
However there are some problems left as far as the rubber cords 82 are concerned since rebound force of the rubber cords 82 given by moving about in the space 84 is weak and the rubber cords 82 are susceptible to deterioration causing slackness and snap that may result in frequent replacement of the rubber cords 82.